Flexible mount for a mechanism

ABSTRACT

Disclosed are techniques and apparatus for flexibly mounting a mechanism. The embodiments describe a flexible mount that is at once tolerant of misalignment, shock resistant, insensitive to rotational orientation, compact, and failure resistant. A mechanism is rigidly attached to a retainer that interlocks with a stationary housing and confines and compresses annular resilient members. The methods may in particular apply to the mounting of hydraulic and pneumatic cylinders for actuation of a shutter assembly in an optical system. In addition the techniques can apply to the flexible mounting of other mechanisms incorporating movable members having axes of symmetry, including push rods and rotating shafts.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.08/900,203, filed Jul. 24, 1997, entitled “Flexible Mount forHydraulic/Pneumatic Cylinder and the Like”, by Paul S. Thompson, whichis incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to a flexible mounting apparatus andmethod for supporting a hydraulic or pneumatic cylinder and pistonmechanism, particularly in conjunction with lasers and optical systems.

BACKGROUND

Pneumatic and hydraulic cylinders are commonly used in a variety ofapplications. In laser and optical systems, it is often important toopen and block the optical transmission path remotely on command. Forthis purpose pneumatic or hydraulic cylinders are frequently used toactuate an optical shutter mechanism. Generally a shutter blocks thelaser output beam or optical transmission path unless it is deliberatelyremoved from the beam or path. Often the shutter incorporates a mirrorsurface disposed at an angle with respect to the beam, such that theblocked beam is deflected from its normal path into an optical absorberor “beam dump.”

Commonly the shutter is rigidly mounted to a mechanical stage thatslides on a rail disposed at substantially a right angle to the beampath. Actuation of the shutter is effected by the extension andretraction of a piston rod attached to the mechanical stage and drivenby pressurized gas or hydraulic fluid in a pneumatic or hydrauliccylinder. A piston connected to a piston rod is slidably mountedinternal to the cylinder. A system of valves admits pressurizedhydraulic fluid or compressed gas, for example air, into the cyinder onone side of the piston, whereupon the piston and connected rod translateaxially under the force created by the pressure differential across thecylinder. Depending on which side of the piston is pressurized, the rodeither extends or retracts until it reaches the limit of its travel,typically controlled by stops internal to the cylinder. The direction ofmotion reverses when the pressure differential reverses under control ofthe valves, or when the pressure is released through a valve and thepiston motion is reversed under spring tension. When the rod isextended, the beam path is blocked; when the rod is retracted, the beampath is open. For safety reasons the cylinder is generally configured sothat the rod is normally extended, and thus the optical path is blocked,if the cylinder is not pressurized.

Alignment of the piston rod axis with the slide rails for the shutterstage can be critical. Unless these are parallel, the mechanism may bindmechanically. This can result in friction, uneven travel of the shutterstage, chatter and vibration, improper positioning of the shutter,jamming of the shutter mechanism, or damage to the sliding stage, rod,or cylinder. Cylinders are generally mounted rigidly to a system baseplate or housing. FIG. 1 illustrates an example of this prior artmethod. Small offsets or angular misalignments between the cylinder axisand the slide rails can lead to catastrophic shutter failure.

Achieving the required alignment upon assembly and installation of ashutter is typically a highly sensitive, skill-intensive, andtime-consuming operation, involving successive minute adjustments of themechanical components interspersed with sequential loosenings andtightenings of the associated fasteners. It would be highly desirable tohave a cylinder mount that could accommodate small to moderate offsetsand angular misalignments of the cylinder axis, allowing the latter toconform automatically to the slide rail axis.

Misalignment solutions typically take the form of couplers, generallyattached to the end of the rod distal to the cylinder, that offerlatitude in tilt, offset, or both. One version uses an elastomericcoupler that flexes. Although it may isolate shock somewhat, it can alsofail, causing the rod to become separated from the load. None of theseflexible couplers facilitates freedom of rotational orientation, and theadditional length of the coupler cannot always be tolerated. Examplesare DMA-series cylinder rod couplers manufactured by the Mead company ofChicago, Ill.; cylinder rod couplers manufactured by Compact AirProducts, Inc., of Westminster, S.C. (Bulletin #CRC); and NJ-seriescylinder rod couplers manufactured by SMC Pneumatics, Inc., ofIndianapolis, Ind.

It would also be desirable to have a cylinder mount that could providecushioning of mechanical shocks that occur at the ends of the pistonstroke. Inadequately damped mechanical shock can produce excess noise,vibration of the mechanical and optical assemblies, and wear or earlyfailure of components.

Shock management can be handled a number of ways, but usually byisolation or absorption. Hydraulic or pneumatic dampeners absorb theshock, converting the energy to heat. These shock absorbers are mountedso that the load contacts a piston rod just before the end of a stroke.This slows the load before it strikes a solid stop. These dampeners areeffective, but they are expensive and require extra space. A more commonmethod is to place resilient bumpers on the piston inside the cylinder.This does an adequate job and adds little to space, but it does notfacilitate alignment or rotation at all. Examples are CF-series,CR-series, and CB-series cushions manufactured by the Mead company ofChicago, Ill.; and NCG-series and NCJ-series cylinders manufactured bySMC Pneumatics, Inc., of Indianapolis, Ind.

An additional desirable feature would be the ability to mount thecylinder at any rotational orientation about its own axis. This wouldprovide flexibility for convenient access to any fittings located on theside wall of the cylinder.

Rotational orientation of the fitting is possible with two types ofmount. The main body of the cylinder can be clamped in a squeeze blockthat, in turn, is mounted to a system support member. Prior totightening the clamping fasteners, the cylinder can be rotated at willabout the piston rod axis. A threaded-nose cylinder protruding through abracket can be oriented as needed before tightening a nut on the otherside of the bracket, although this is limited to situations that allowaccess to the nut. Neither type allows for misalignment or shockisolation. Examples are 12000-series cylinder-mounting squeeze blocksand 15000-series foot mounting brackets manufactured by ClippardInstrument Laboratory of Cincinnati, Ohio.

Another shortcoming of existing cylinder mounts is the difficulty ofthreading the piston rod into a load or other object. Existing versionsrequire an estimate of when to engage the cylinder nose threads in orderto achieve the proper tightened depth of the threaded rod. Alternativelya tool must be used to grip and twist the rod to achieve proper depth.This may be difficult to access and vulnerable to scratching the rodsurface, which is polished to form a sliding seal with the nose of thecylinder.

Compactness would be an attractive feature of any improved cylindermounting solution. Space is typically at a premium in any laser oroptical system. In particular, compactness is important if the improvedmount is to be retrofitted into an existing system or design, wheredimensional constraints are generally already fixed.

Accordingly, there is a need for a hydraulic or pneumatic cylinder mountthat is simultaneously self-aligning, shock-isolating, insensitive torotational orientation, and compact. There is no known device thatprovides all of these features and only one known device that providestwo features out of the four. All known devices that correct formisalignment add to the overall length of an assembly, thus requiringredesign and making retrofitting difficult or impossible.

SUMMARY

The present flexible mount is unique in that it is self-aligning,isolates shock, permits rotational orientation as desired, and typicallyfits within little more space than a conventional solid threaded mount.In one embodiment the invention comprises a compact mounting adapter forthreaded-nose hydraulic or pneumatic cylinders to replace a rigidthreaded mount with a flexible one that provides shock isolation,self-alignment capability and orientation insensitivity withinsubstantially the same compact space. The cylinder threads into theflexible mounting adapter that, in turn, mounts rigidly into a supportstructure of the system. In one embodiment resilient “O”-rings are usedto support the cylinder and isolate it within the mount. A suitableretainer prevents separation of the cylinder from the mount and limitsor influences movement of the cylinder within the mount. A resilientmount allows the cylinder to tilt in the event of angular misalignment,thus relieving side loads that might cause binding, and it reduces thetransmission of shock and noise to the mounting structure. It alsoallows the cylinder to rotate about its own axis with any orientation,so that features or fittings on the side of the cylinder can bepositioned as desired, and facilitates threading of the piston rod withaccurate depth into a load or other object.

The mount protects the cylinder mechanism against damage from excessiveside loads applied to the mechanism body, as when using the cylinderbody as a handle for carrying an assembly. It also protects againstdamage to the mount itself. A collar integral with the mount housingencircles the cylinder body with clearance and acts as a rigid stop tolimit lateral tilt and offset displacement. This is augmented by asecond rigid stop defined by clearance between the outer diameter of aflange of the retainer and the walls of a counterbore in the mounthousing. These solid stops limit side loading of the resilient membersand prevent excessive tilt that could deform or damage a cylindermechanism.

In one preferred embodiment the retainer may incorporate locking threadson its inside diameter. The outside diameter of the retainer serves inturn as an inner diameter for two “O”-rings and also as a longitudinalend wall for one of these “O”-rings.

The flexible mount fits within substantially the same length as theconventional rigid threaded mount and, therefore, does not requirerelocation of the cylinder for a redesign or retrofit. Furthermore, aretrofit is cosmetically substantially identical with the original rigidthreaded mount.

In a preferred embodiment the retainer tightens and seats solidlyagainst a rigid surface of a cylinder. This positive positioning makesthe elastic and frictional properties of the mount independent of torqueapplied to tighten the retainer during assembly of the mount, whereasseating against a non-rigid surface would render these propertiestorque-dependent. Rigid seating furthermore prevents the retainer fromloosening during operation. Thus the tightness of the retainer is notaffected by aging, shrinkage, or failure of the elastomeric members ofthe mount. Even in the event of total failure or disintegration of the“O”-rings, the retainer maintains its position, thus interlocking thecylinder with the mount, allowing the cylinder mechanism to remainsupported in the mount and to function.

In a preferred embodiment the elastomeric members are alwayscompressively loaded, with the load limited by rigid stops. Additionalprotection is gained by designing the mount so that the elastomericmembers are substantially confined within annular-shaped cavitiesdefined by rigid walls on inner and outer diameters and on both frontand rear longitudinal surfaces, such that deformation of the elastomericmembers is restricted in every direction. Once the cavity is totallyfilled with elastomer, this results in a rapid rise in spring constantto that exhibited in hydrostatic compression of a solid material.

The embodiments thus provide a flexible cylinder mount that is at oncetolerant of misalignment, shock resistant, insensitive to rotationalorientation, compact, and failure resistant.

In addition to hydraulic and pneumatic cylinders, the invention isapplicable to the flexible mounting of other mechanisms incorporatingreciprocating or rotating members having axes of symmetry, includingpush rods and rotating shafts.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a prior art cylinder mounting arrangement.

FIG. 2 illustrates a first embodiment of the present invention.

FIG. 3 illustrates a second embodiment of the present invention.

FIG. 4 illustrates a third embodiment of the present invention.

FIG. 5 illustrates a fourth embodiment of the present invention.

FIG. 6 illustrates a flange mounted version of the preferredembodiments.

FIG. 7 illustrates the integration of an embodiment with the shutterassembly of a laser or optical system.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 illustrates the rigid mounting arrangement 10 of a hydraulic orpneumatic cylinder 12 in accordance with the prior art. Cylinder 12comprises a cylinder body 14, a piston rod 16 rigidly connected to apiston (not shown) which is slidably mounted internal to cylinder body14, and a threaded nose section 18, typically containing externalthreads 20, a thread relief 22, an annular boss 24 concentric with theaxis of rod 16, and a solid end wall 25. Cylinder body 14 may alsocontain a side fitting 26 for the purpose of connecting to a supply ofpressurized hydraulic fluid or gas 36 (see FIG. 2), for examplecompressed air, to actuate the piston. In accordance with the prior art,cylinder 12 is mounted rigidly to a system bulkhead 28 by engagingexternal threads 20 with internal threads 30 in bulkhead 28 andtightening securely to press end wall 25 of cylinder 12 against anannular seat 32 at the bottom of a counterbore 34 concentric with theaxis of internal threads 30 in bulkhead 28. This rigid mountingarrangement has the disadvantages of allowing no lateral misalignmentwithout deformation or damage to cylinder 12 or piston rod 16; providinglittle or no mechanical shock absorption; and permitting no latitude forrotational orientation to determine the location of side fitting 26.

FIG. 2 illustrates a piston and cylinder arrangement incorporating oneembodiment of the present invention, in which features of the prior artrigid mounting arrangement 10 are replaced by features of a flexiblemounting arrangement 40. Cylinder 12 threads into a flexible mountingadapter 42 that, in turn, is rigidly fastened to a support member, forexample a bulkhead (not shown) of the system. In mounting arrangement40, resilient “O”-rings 44, 46 are used to support the cylinder andisolate it within a housing 48. A retainer 50 prevents separation ofthreaded cylinder nose 18 from housing 48 and limits or influencesmovement of the cylinder within the housing.

The resilient material of the “O”-rings is preferably elastomericsilicone rubber or nitrile, and their sizes and durometer ratings areselected for compatibility with the dimensions and loading of thecylinder in accordance with engineering principles familiar in the art.“O”-rings of various cross-sectional shapes may be used, depending onengineering preference. These cross-sectional shapes include circular,four-lobe or “quad ring,” and square (commonly described as lathe-cut).

The materials from which housing 48 and retainer 50 may be fabricatedinclude metals, rigid plastics, composites, and other durable, rigidstructural materials. Fabrication processes may include machining,casting, molding, stamping, and combinations thereof.

A collar 52 integral with housing 48 at one end, for conveniencedesignated as the rear end, encircles the periphery of cylinder body 14inside a counterbore 54 with an annular clearance 56, and acts as arigid stop to limit lateral tilt and displacement of cylinder 12. Asecond counterbore 58 concentric with counterbore 54 is contained in theopposite end of housing 48, for convenience designated as the front end.Housing 48 also contains a through hole diameter 60, 61 through aninternal step 62 and concentric with front and rear counterbores 58 and54.

Retainer 50 incorporates inside threads 64 which engage external threads20 on the nose section of cylinder 12. Inside threads 64 may compriselocking threads. The rear face 66 of retainer 50 is securely tightenedagainst end wall 25 of cylinder 12. The front face 68 of retainer 50 maybe slotted radially for insertion of a blade, tangs, or otherappropriate tool, or may be otherwise configured to facilitatetightening.

The outside diameter 70 of retainer 50, smaller than the inside diameterof through hole 60, 61, serves in turn as an inner diameter for“O”-rings 44, 46. Retainer 50 also incorporates a flange 72 having aninner face 74 that serves as an end wall for the front “O”-ring 44.Flange 72 prevents retainer 50 from passing entirely through housing 48.An annular clearance 76 between the outer diameter of flange 72 and theinner diameter of front counterbore 58 defines an auxiliary rigid stopas a back-up to rear clearance 56 to limit side loading of the resilient“O”-rings 44, 46 and prevent excessive tilt that could deform thecylinder mechanism.

In a preferred embodiment retainer 50 tightens and seats solidly againstrigid end wall 25 of cylinder 12 by means of inside threads 64 ofretainer 50 engaging external threads 20 of cylinder 12. Flange 72 ofretainer 50 thereby interlocks cylinder 12 with housing 48 and produceslongitudinally compressive forces on “O”-rings 44, 46. In otherembodiments a means to attach retainer 50 rigidly to cylinder 12 maycomprise press fitting or individual fasteners. The positive seating ofrigid retainer 50 against rigid cylinder end wall 25 keeps the elasticand frictional properties of the mount independent of torque applied totighten retainer 50 against cylinder wall 25, whereas seating against anon-rigid surface would render these properties torque-dependent. Rigidseating furthermore prevents retainer 50 from loosening duringoperation. The tightness of retainer 50 will therefore not be affectedby aging, shrinkage, or failure of elastomeric “O”-rings 44, 46 of themount. Even in the event of complete failure or disintegration of“O”-rings 44, 46, retainer 50 maintains its position, and cylinder 12remains interlocked with the mount and functional.

To assemble, front “O”-ring 44 is placed around outside diameter 70 ofretainer 50 adjacent to flange 72. This subassembly is then insertedinto housing 48 such that front “O”-ring 44 and flange 72 are recessedwithin front counterbore 58 of housing 48 and outside diameter 70 ofretainer 50 extends through the through hole diameter 60, 61 of housing48. Rear “O”-ring 46 is recessed between outside diameter 70 of retainer50 and rear counterbore 54 of housing 48. Threaded nose 18 and end wall25 of cylinder 12 are then inserted into counterbore 54 such that pistonrod 16 is substantially concentric with the axis of retainer 50.External threads 20 of cylinder 12 engage inside threads 64 of retainer50. The rotational orientation of cylinder 12 is adjusted as desired,and retainer 50 is tightened rigidly against cylinder end wall 25 usingan appropriate tool. The entire cylinder and mount assembly 40 may thenbe fastened as a unit to a system support member or bulkhead,pressurized gas or hydraulic fittings may be installed, and the pistonrod 16 may be connected to a load.

Although preferably integrally formed with retainer 50, flange 72 mayalternatively be threaded, press fit, soldered, welded, secured byindividual fasteners, or otherwise rigidly affixed to retainer 50.Although the geometry of flange 72 as hereinabove described issubstantially annular, other shapes that extend beyond outside diameter70 of retainer 50 may be employed, including but not limited to toothedwheel and cruciform shapes.

In a preferred embodiment the elastomeric members, for example “O”-rings44, 46, are always compressively loaded, with limitation of the load byrigid stops. Additional protection is gained by designing mount 42 sothat elastomeric members, for example “O”-rings 44, 46, reside inannular-shaped cavities defined by rigid walls on inner and outerdiameters and on both front and rear longitudinal surfaces, such thatthe deformation of elastomeric members is restricted in every direction.This results in a rapid rise in spring constant to that of hydrostaticcompression of a solid, once the cavity is totally filled withelastomer.

Certain design parameters are of particular importance. These relate tocontrol of the radial and longitudinal deformations of both front andrear “O”-rings 44, 46, and to the annular clearances, in particular rearclearance 56. Clearance 56 dictates the maximum lateral tilt or offsetof cylinder 12. Radial deformation of either “O”-ring 44, 46 affects itselastic, frictional, and drag properties, and the radial deformation ofeither “O”-ring 44, 46 affects the longitudinal position of both“O”-rings. It is advisable to minimize deformation of rear “O”-ring 46,thereby minimizing its influence on drag and longitudinal position.These design objectives can be achieved through careful control of thedimensions of mount housing 48 and retainer 50, using a knowledge of the“O”-ring properties and system loads, and applying engineering anddesign methods familiar in the art.

Hereinabove described flexible mount 42 allows cylinder 12 to tilt inthe event of angular misalignment, thus relieving side loads that maycause binding, and it reduces the transmission of shock and noise to themounting structure. It also allows cylinder 12 to be rotated about itsown axis to any orientation, so that features or fittings on the side ofthe cylinder can be positioned as needed. Flexible mount 42 fits withinsubstantially the same length as a conventional rigid threaded mountand, therefore, does not require relocation of the cylinder for aredesign or retrofit. Furthermore, the retrofit may be cosmeticallysubstantially identical with the replaced rigidly threaded mount.

Flexible mount 42 protects cylinder mechanism 12 against damage fromexcessive side loads applied to cylinder body 14, as when using thecylinder body as a handle for carrying an assembly. It also protectsagainst damage to mount 42 itself.

Embodiment 40 thus provides a flexible cylinder mount that is at oncetolerant of misalignment, shock resistant, insensitive to rotationalorientation, compact, and failure resistant.

Intact “O”-rings 44, 46 in hereinabove described embodiment 40 mayprovide the additional benefit of a fluid, pressure, or vacuum seal toisolate the space surrounding body 14 of cylinder 12 from the spacesurrounding front end 18 of cylinder 12 and piston rod 16, facilitatingthe use of embodiment 40 in a situation in which different media fillthe respective spaces.

FIG. 3 illustrates a second embodiment 80 of the invention, wherein asingle elastomeric member, for example “O”-ring 82, is used at only oneend of a mount 84, thereby providing rigidity in one direction and shockabsorption in the other direction. Flange 72 of retainer 50 seats withincounterbore 58 of mount 84 under the compressive force exerted by“O”-ring 82. Therefore, as illustrated cylinder 12 is rigidly preventedfrom longitudinal motion in the rearward direction, but may movelongitudinally against the shock absorbing cushion of “O”-ring 82 in theforward direction, and may tilt laterally about a pivot defined byflange 72 and counterbore 58. Annular clearance 86 is provided betweencylinder 12 and counterbore 88 of mount 84, which limits side loading of“O”-ring 82 and limits the maximum lateral tilt or offset of cylinder12.

In a variation of embodiment 80, single elastomeric “O”-ring 82 may bepositioned in the opposite end of mount 84 between retainer flange 72and counterbore 58. In the latter variation, operation would be similarto that of embodiment 80 described hereinabove, except that forward andrearward directions would be reversed.

FIG. 4 illustrates a third preferred embodiment 90 of the invention, inwhich elastomeric “O”-rings are replaced by spring washers 92, 94.Spring washers 92, 94 are assembled under compression longitudinallybetween retainer flange 72 and cylinder end wall 25 and with clearanceradially between retainer 50 and housing 48. In this configurationspring washers 92, 94 provide resilient mounting to cylinder 12,providing lateral tilt and offset misalignment capability, shockabsorption, and rotational orientation insensitivity. A variety ofspring washer familiar in the art is known as a “Belleville Washer.”Embodiment 90 may be attractive in situations in which spring washersmay be preferred over elastomeric “O”-rings because of greaterdurability.

FIG. 5 illustrates a hybrid embodiment 100 in which one resilient membercomprises an “O”-ring 102 and a second resilient member comprises aspring washer 104. Assembly and operation are substantially the same asfor the embodiments 40 and 90 illustrated respectively in FIG. 2 andFIG. 4. A potential application of embodiment 100 may be to takeadvantage of the sealing properties of an elastomer and the durabilityof a spring washer, particularly if the front and rear ends of housing48 are subjected to different environmental conditions.

As illustrated in FIG. 2, flexible mount housing 48 may be fabricatedwith external threads 108 so that the entire cylinder and flexible mountassembly may be threaded as a unit into a system bulkhead or othersupport member in substantially the same manner as a rigidly mountedcylinder illustrated in FIG. 1. External threads 108 are applicable toall of the hereinabove described embodiments and may in particularfacilitate retrofitting.

As illustrated in FIG. 6, a flexible mount housing 110 may be fabricatedwith a flange 112, by which the cylinder and flexible mount assembly maybe attached as a unit to a system bulkhead or other support member bymeans of appropriate fasteners. Flanged mount housing 110 is applicableto all of the hereinabove described embodiments. Other methods ofattachment to a system bulkhead or support member include structuresincorporating the principal features of housing 48, for exampleincorporating the housing function integral with a system bulkhead orsupport member.

An example of the use of the invention in conjunction with the controlof a shutter assembly in a laser or optical system 120 is illustrated inFIG. 7. An incident optical beam 122 enters optical system 120 and isblocked by a shutter assembly 124. Shutter assembly 124 incorporates anoptically reflective surface 126 disposed at an angle with respect toincident optical beam 122. Reflective surface 126 deflects incidentoptical beam 122 from its original path into a reflected optical beam128, which may then propagate to a different part of the system or to anoptical absorber or “beam dump” (not shown). Shutter assembly 124 alsoincorporates a mechanical stage 130, which is slidably mounted to rails(not shown) disposed transversely to incident optical beam 122.Mechanical stage 130 is connected rigidly to piston rod 16 of hydraulicor pneumatic cylinder 12, which in turn is mounted in accordance withthe invention within flexible mount housing 48. Housing 48 in turn isfastened rigidly to a support member 134 of system 120, such that theaxis of cylinder 12 and piston rod 16 is substantially parallel with therails.

In operation, control valves (not shown) admit pressurized gas orhydraulic fluid into cylinder 12, causing piston rod 16 to retract intocylinder 12, drawing shutter assembly 124 toward cylinder 12, andthereby permitting the undeflected optical beam to propagate through anaperture 136. When the control valves release the pressurized gas orhydraulic fluid from cylinder 12, piston rod 16 is extended through theforce of springs mounted internal to cylinder 12, thereby returningshutter assembly 124 along the rails to its original beam deflectingposition.

Flexibly mounting of cylinder 12 within housing 48 as described in theembodiments permits offset and tilt misalignment of the cylinder withinhousing 48, allowing alignment of the cylinder to be dictated by theaxis of the rails on which shutter assembly 124 traverses. Thiseliminates tedious manual alignment procedures and prevents binding ofthe mechanism, which may otherwise lead to friction, uneven travel ofmechanical stage 130, chatter, vibration, improper positioning orjamming of shutter assembly 124, or damage to mechanical stage 130,piston rod 16, or cylinder 12.

Mounting of cylinder 12 in accordance with the embodiments also providescushioning of mechanical shock and permits discretionary rotationalorientation of cylinder 12 to facilitate access to side fittings 26.

The hereinabove embodiments describe flexible mounts generallyconfigured separately from and attachable to supported mechanisms, forexample pneumatic or hydraulic cylinders, and therefore potentiallyuseful for retrofitting. However, the techniques hereinabove disclosedmay also be applied to other configurations, for example a flexiblemounting structure manufactured integrally with a supported mechanism.In addition to hydraulic and pneumatic cylinders, the invention isapplicable to the flexible mounting of other mechanisms incorporatingreciprocating or rotating mechanisms having axes of symmetry, includingpush rods and rotating shafts.

While particular embodiments of the present invention have been shownand described, it will be obvious to those skilled in the art thatchanges and modifications may be made without departing from thisinvention in its broader aspects and, therefore, the appended claims areto encompass within their scope all such changes and modifications asfall within the true spirit and scope of this invention.

What is claimed is:
 1. An apparatus comprising: a rigid housingincorporating a through hole with a through hole diameter and comprisingat least one counterbore having a diameter larger than said diameter ofsaid through hole, said through hole and said at least one counterborebeing concentric about a common housing axis; at least one resilientmember; and a retainer having an outside cylindrical surface, at leastone end of said outside cylindrical surface having a diameter smallerthan said through hole diameter, said retainer rigidly attached to amechanism incorporating a movable rod, such that said retainer is heldcaptive within said housing.
 2. An apparatus comprising: a rigid housingincorporating a through hole with a through hole diameter; at least oneresilient member; a retainer having an outside cylindrical surface, atleast one end of said outside cylindrical surface having a diametersmaller than said through hole diameter, said retainer rigidly attachedto a mechanism; at least one counterbore; and an outer flange affixed tosaid retainer, an outer diameter of said flange being larger than saidthrough hole diameter and smaller than a diameter of said at least onecounterbore.
 3. The apparatus of claim 2 wherein said at least oneresilient member is selected from the group consisting of a springwasher and an elastomeric O-ring.
 4. The apparatus of claim 2 whereinsaid retainer comprises inside threads and said outer flange is affixedto said retainer and adjacent to an end of said retainer distal fromsaid mechanism.
 5. The apparatus of claim 2 wherein said housing furthercomprises a counterbore encircling a periphery of said mechanism,thereby creating a substantially annular clearance between said housingand said mechanism.
 6. The apparatus of claim 2 wherein said mechanismincorporates a rotating shaft.
 7. The apparatus of claim 2 wherein saidmechanism incorporates a reciprocating rod.
 8. The apparatus of claim 7wherein said reciprocating rod is connected to a piston slidablycontained within a hydraulic or pneumatic cylinder.
 9. The apparatus ofclaim 8 wherein said reciprocating rod is further attached to a loadcomprising a shutter assembly in an optical system.
 10. An apparatuscomprising: a rigid housing incorporating a through hole with a throughhole diameter; at least one resilient member; and a retainer having anoutside cylindrical surface, at least one end of said outsidecylindrical surface having a diameter smaller than said through holediameter, said retainer rigidly attached to a mechanism, wherein saidmechanism incorporates a rotating shaft.
 11. The apparatus of claim 10wherein said at least one resilient member is selected from a groupconsisting of an elastomeric O-ring and a spring washer.
 12. Theapparatus of claim 10, further comprising: at least one counterbore; andan outer flange affixed to said retainer, an outer diameter of saidflange being larger than said through hole diameter and smaller than adiameter of said at least one counterbore.
 13. The apparatus of claim 10wherein said retainer comprises inside threads and an outer flangeaffixed to said retainer and adjacent to an end of said retainer distalfrom said mechanism.
 14. The apparatus of claim 10 wherein said housingfurther comprises a counterbore encircling a periphery of saidmechanism, thereby creating a substantially annular clearance betweensaid housing and said mechanism.
 15. An apparatus comprising: a rigidhousing incorporating a through hole with a through hole diameter; atleast one resilient member; and a retainer having an outside cylindricalsurface, at least one end of said outside cylindrical surface having adiameter smaller than said through hole diameter, said retainer rigidlyattached to a mechanism, wherein said mechanism incorporates areciprocating rod.
 16. The apparatus of claim 15 wherein said at leastone resilient member is selected from a group consisting of anelastomeric O-ring and a spring washer.
 17. The apparatus of claim 15,wherein said retainer comprises inside threads and an outer flangeaffixed to said retainer and adjacent to an end of said retainer distalfrom said mechanism.
 18. The apparatus of claim 15 wherein said housingfurther comprises a counterbore encircling a periphery of saidmechanism, thereby creating a substantially annular clearance betweensaid housing and said mechanism.
 19. The apparatus of claim 15, whereinsaid reciprocating rod is connected to a piston slidably containedwithin a hydraulic or pneumatic cylinder.
 20. The apparatus of claim 19wherein said reciprocating rod is further attached to a load comprisinga shutter assembly in an optical system.